<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Document</title>
</head>

<body>
  <script>
    const keyA = {
      a: 1,
    };
    const keyB = {
      b: 1,
    };
    const keyC = "12";
    const myObj = {
      [keyA]: "valueA",
      [keyB]: "valueBX",
      keyC: "valuec",
    };
    console.log(myObj["keyC"]);
  </script>
</body>

</html>